Collected photo

PARIS, June 19, 2025 (BSS/AFP) - Arctic peatlands are expanding as the 
climate warms, new research showed Thursday, a change that could slow global 
heating in the near term but have the opposite effect in future.

Peatlands are the largest terrestrial store of carbon, locking away twice as 
much heat-trapping CO2 from the atmosphere in their waterlogged soils as all 
the world's forests.

These carbon-rich reservoirs, composed of partially decayed organic matter, 
only cover three percent of Earth's surface, and generally fade out in the 
far north where harsh weather limits plant growth.

But warmer temperatures caused by climate change have improved growing 
conditions for plants in the Arctic, and satellite data has shown a general 
"greening" of this frosty region.

Using drones, satellite imagery and on-the-ground observations, an 
international team of scientists assessed peatlands in the European and 
Canadian Arctic to see if they had benefited from warmer climes.

They found strong evidence that peatlands "have likely undergone lateral 
expansion over the last 40 years" in the Arctic, which is the fastest warming 
region on Earth.

"The permafrost thaws a little, provides a water source for vegetation, and 
surface vegetation recovers. In this study, we specifically see a lateral 
expansion," Michelle Garneau, a professor at the University of Quebec in 
Montreal, and co-author of the study, told AFP.

The most marked change was observed where summer temperatures have risen the 
most, such as in the Norwegian archipelago of Svalbard.

"All these new vegetated surfaces that didn't exist three decades ago are 
currently actively absorbing carbon," Garneau added.

This suggests Arctic peatlands "are an increasingly important natural carbon 
sink, at least in the near term", said study co-author Karen Anderson, a 
professor from the University of Exeter, which led the research.

But how they respond to climate change in future is "still highly uncertain", 
said the study published in the peer-reviewed journal Communications Earth 
and Environment.

Recent modelling suggests that northern peatlands "may become a carbon source 
from mid-century" as they dry out and permafrost thaws, the study said.

They are also at risk from wildfires, which release masses of stored up 
carbon at once.

"If temperatures continue to rise, we are likely to see changes in rainfall, 
and we are not sure how sustainable new or existing peatlands will be," said 
Anderson.

More peatlands also means more natural emissions of methane, a potent 
greenhouse gas far more effective at trapping heat than CO2.

"So while our study gives us some positive news, it does not detract from the 
urgent need to reduce greenhouse gas emissions and stabilise our climate," 
said Anderson.